Frequency determining unit



Aug. 6, 1946.

s. A. BOKOVOY ETAL I, FREQUENCY DETERMININING UNIT Filed Aug. 39, 1944 v INVENTORS- SJMz/FA ,4. 60mm) BY M4445 STU/V72 Patented Aug. 6, 1946 UNITED STATES PATENT OFFICE FREQUEN CY DETERIWIINING UNIT Application August 30, 1944, Serial No. 551,984

7 Claims. (Cl. 171-327) Fhis invention relates to oscillator or resonator units for crystal controlled oscillator circuits. It consists of an improved and simplified structural arrangement specially designed to reduce the number of parts to a minimum. As a result there is substantial economy in costs and labor in production, including reduced tooling, stocking of parts and fewer operations in assembling. It further ofiers material advantages over constructions as heretofore employed particularly with respect to the total elimination of welding or soldering required in the making of a holder unit having rigidly secured terminals and contact members. Thereby there is avoided all danger of detrimental efiect incident to loose solder or flux acid influence on the contacts and contained parts. The improved features and structure are such as to be particularly well adapted for incorporation in the end or top loading, plug-in terminal types of resonator units wherein a maximum of compactness is desirable. Its features are further specially adapted for units of the type having generally rectangular sockets for the insert elements and wherein provision is made for electrical contact at diagonally opposite corners of the socket, an arrangement suitable to many desirable types of crystal mounting.

The described and other features and advantages of the present invention will be more fully understood by reference to the accompanying drawing wherein like reference characters are applied to the corresponding parts in the several views.

In the drawing:

Fig. 1 is a view in side elevation of the improved oscillator unit;

Fig. 2 is a plan view thereof with the cover removed;

Fig. 3 is a central, longitudinal vertical section of the housing, crystal and contact assembly forming the resonator unit;

Fig. 4 is a cross sectional view at right angles thereto;

Fig. 5 is a longitudinal sectional view of the cover member, and

Fig. 6 is a perspective view of the improved combined terminal pin and contact.

In the preferred embodiment of the invention as herein disclosed the housing or holder for the crystal element and the contacts and mounting parts is formed of molded insulating material consisting of an inclosing body or base portion 1 formed with a top opening, rectangular socket 2 for the insert parts and to which is attached,

with the interposition of a resilient sealing washer 3, a cover member 4, likewise of molded insulating material. As indicated the cover is secured by means of securing screws 5, countersunk and passed through apertures 6 in the cover and secured to threaded apertures l in the housingbody portion. The socket 2 formed in the body member I is of rectangular cross sectional contour having its side and end walls parallel to the similarly contoured external surface of the body portion and has its bottom wall formed with symmetrically disposed transversely extending bosses 8 to provide for a limited area supporting contact with the insert elements.

The dimensions of the socket as will be appreciated are such as to receive the usual insert elements composed of the crystal 9 and cooperating oppositely positioned, electrodes It which are of rectangular plate formation and of a relative size to be received by the socket in a manner to insure of positioning in proper cooperative relation for attaining the desired resonant action. The width of the socket is likewise such as to permit of the reception of the coil spring I I having the turns thereof at its opposite extremities enlarged to be of a, diameter substantially corresponding to the longitudinal dimension of the socket portion with the required tolerance for its reception. The action of the coil spring in its interposed position as shown is to exert on or transmit to the electrodes and crystal a compressive force proportioned to maintain good electrical contact therebetween and likewise to maintain a similar compressive engagement with cooperating contact elements in an improved arrangement as now to be described.

The improved contact arrangement in accordance with the present invention provides for a greatly simplified and advantageous structure wherein the usual plug-in type of terminal pins and the contacts or contact plates associated with the respective pins are integrally formed for rigid assembling with the housing by uniting therewith in the molding operation. As a result the production is simplified to a material degree, accurate alignment is readily obtained and also rigidly retained in the assembly. In addition objectionable factors, as presented by welded and soldered assemblies of pins and contacts as heretofore employed, are eliminated. These include, in addition to difiiculties introduced by variations of proper alignment in the assembling of supporting parts where close tolerances are required, danger of electrical disturbance incident to loose solder or improper welding and possibility of dotrimental or corrosive acid influence as a result of the use of soldering fluxes.

As best shown in Figs. 3, 4 and 6, in the improved contact arrangement of the present invention the terminal pins l2, having the usual rounded extremities for plug-in electrical connection, are formed at their inner portions with deformations or bonding ribs I 3 for mechanical bonding with the molded housing and have integrally formed therewith the inwardly or upwardly extended contact plates Id. The contact extension is desirably of flattened or plate formation, extending parallel to the axis of the pin, and has its upper extremity beveled or tapered at its inner side. As assembled by molding with the housing the contact plate extensions of the respective pins are oppositely positioned and partially embedded in the side walls of the housing so as to occupy diagonally opposite corner positions in the rectangular socket with inward exposure of the contact surfaces. They accordingly provide contact surfaces of vertical shoulder or flattened rib like formation projecting within the socket and provided with tapered upper or entry portions. In cooperating and symmetrical relation thereto the housing is formed with complementary vertical bearing ribs or shoulders i5 similarly projected within the socket at the other of the diagonally opposite corners thereof. These shoulders are likewise formed with tapered upper portions for inward deflection of the insert elements and provide, with the contact extensions, symmetrically disposed bearing shoulders or surfaces for engagement by the insert elements. The insert elements, comprising the resonator or crystal, the electrode plates on each side thereof and the spring are assembled as indicated. They are inserted from the top into the socket with one of the electrodes, the left hand electrode as shown, engaging one of the contacts [4 along one vertical marginal edge and engaging the housing shoulder at its opposite vertical marginal position. The opposite electrode is electrically connected with the opposite contact extension by means of the interposed spring II engaged therewith and having its outer enlarged coil in pressure engagement with th opposite or right hand contact extension and, in balanced supporting relation, with the opposite, right hand, housing shoulder it. There is thus produced an improved resonator unit of utmost simplicity of structure, permissive of substantial economies in production and assembly and offering material, practical advantages in use over constructions as heretofore made.

As will be appreciated different sizes of crystals may be accommodated by varying the dimensions of the socket formed in the housing. Also, while the cover is shown as secured by screws with an interposed washer, it will be understood that the device may be further simplified by securing of the cover directly to the housing by a suitable cement such as with a polystyrene cement thereby providing a seal of a more permanent character.

As shown in Fig. 5 the cover member is formed on its under or inner side with integrally transverse ribs !6 operative in a manner similar to that of the housing ribs 8 to provide limited area contact with the insert elements for reduction in damping of the desired vibrations.

What is claimed is:

1. A frequency determining unit of the character described comprising a housing member provided with a socket for th reception of a resonator element, said housing being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact portions extending within the socket, a crystal element and opposite electrodes associated therewith received within the socket with one electrode engaging one of the contact plates and a spring interposed to engage the opposite of said electrodes and the other of said contact plates for closing of the electrical circuit.

2. A frequency determining unit of the character described comprising a housing member provided with a rectangular socket for the reception of a resonator element, said housin being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact portions vertically extending within diagonally opposite corner positions of the socket, a crystal element and opposite electrodes associated therewith received within the socket with one electrode engaging one of the contact plates and a coil spring interposed to engage the opposite of said electrodes and the other of said contact plates for closing of the electrical circuit.

3. A frequency determining unit of the character described comprising a housing member provided with a rectangular socket for the reception of a resonator lement, said housing being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact portions extending within the socket at opposite sides thereof, a crystal element and opposite electrodes associated therewith received within the socket with one electrode engaging one of the contact plates and a coil spring interposed to engage the opposite of said electrodes and the other of said contact plates for closing of the electrical circuit and a cover member secured to the housing for the sealing of the socket.

4. A frequency determining unit of the character described comprising a housing member provided with a socket for the reception of a resonator element, said housing being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact plates extending within the socket at diagonally opposite corners thereof, a crystal element and opposite electrodes associated therewith received within the socket with one electrode engaging one of the contact plates and a coil spring interposed to engage the opposite of said electrodes and the other of said contact plates for closing of the electrical circuit, said contact plates being positioned to project into the socket and said socket having inward shoulder projections diagonally opposite to the contact plates for symmetrical support of the insert parts.

5. A frequency determining unit of the character described comprising a housing member provided with a rectangular socket for the reception of a resonator element, said housing being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact portions vertically extending within diagonally opposite corner positions of the socket, a crystal element and opposite electrodes associated therewith received Within the socket and electrically connected to the contact plates.

6. A frequency determining unit of the character described comprising a housing member procontact plates, said contact plates being positioned to project into the socket and said socket having inward shoulder projections diagonally opposite to the contact plates for symmetrical support of the insert parts.

7. A frequency determining unit of the character described comprising a housing member provided with a rectangular socket for the reception of a resonator element, said housing being of molded insulating material and having integral, combined terminal pin and contact plate elements molded therein and having their contact portions extending within the socket at opposite sides thereof, a crystal element and oppositeelectrodes associated therewith received within the socket and electrically connected with the contact plates, a cover member secured to the housing for the sealing of the socket and said contact plates being partially embedded in the side wall of the socket and having inwardly beveled extremities.

SAMUEL ALEXANDER BOKOVOY.

HANS STUNTZ. 

